All migrant children under age 5 who were separated at the US-Mexico border will have been reunited with their parents by early Thursday morning if they were eligible, a Trump administration official said in a statement on Wednesday.
The American Civil Liberties Union, which sued the government over its separation policies, disputed that assertion.
"Their statement is vague at a minimum," said attorney Lee Gelernt, noting that a San Diego judge had set a deadline of Tuesday for reuniting those children. "We know they missed the deadline."
The government has said some children were not eligible for reunification because the parent was deported, had a criminal record or was otherwise unfit.
US Judge Dana Sabraw in San Diego had ordered the government to reunite the children under the age of 5 by Tuesday and all separated children by July 26.
On Thursday, the government will give Sabraw a progress report on the younger children and whether it expects to meet the deadline for the older group.
The government has said around 2,300 children were separated from their parents at the border under the Trump administration's "zero tolerance" policy on illegal immigration, which was abandoned in June after intense protests.